At present, a double-faced display device that can display an image on both sides of the display is often needed. The double-faced display device may be applied in communication industry, government windows, financial industry, transportation industry, and a business hall in window industries, such as public places with large population such as air ports, railway stations, subway stations, dining rooms, and therefore the double-faced display device has a broad developing potential.
In prior art, a typical structure of a double-faced display device is as shown in FIG. 1, comprising: a liquid crystal layer 40, a first polarizer 41 and a second polarizer 42 on both sides of the liquid crystal layer 40, a front light source system 43 close to a first polarizer side, and a reflective polarizer 44 between the second polarizer 42 and the liquid crystal layer 40. It is to be noted that when an incidence direction of light is consistent with a polarization direction of the reflective polarizer 44, the light may transmit through the reflective polarizer 44, and when the incidence direction is not consistent with the polarization direction, the light is reflected back by the reflective polarizer 44. With such a double-faced display device having this structure, when electric fields on both sides of the liquid crystal layer 10 change, liquid crystal molecules in the liquid crystal layers 40 may be in horizontal and vertical states respectively. When the liquid crystal molecules are in the horizontal state, one face of the display may display an image in a transmission mode; and when the liquid crystal molecules are in the vertical state, the other face of the display may display an image in a reflection mode by the reflective polarizer 44. However, this kind of double-faced liquid crystal display device can not work in these two modes at the same time and thereby can not realize a function of displaying images on both faces at the same time.